Previous studies from this laboratory have demonstrated significantly higher viral genetic diversity and a higher frequency of primary resistance to protease inhibitors (PI) among illicit drug users compared to HIV-1 infected non-drug users. To explore the potential link between drug use and greater viral replication, diversity and antiretroviral resistance, we propose to exploit the findings that 1) cocaine abuse stimulates high levels of the AP-1 transcription factor associated immediate early genes and 2) only about 40% of Clade B infected individuals carry an HIV-1 LTR length polymorphism (MFNLP) containing an AP-1 binding site. Using a large cohort of cocaine using HIV-1 infected subjects followed at the Vanderbilt Clinical Care Center, we will address the hypothesis that cocaine users infected with HIV-1 carrying the Clade B HIV-1 LTR polymorphism with an AP-1 binding site will have higher viral loads, greater genetic diversity, and greater primary resistance to antiretrovirals than either cocaine users whose virus does not carry the LTR polymorphism or non-cocaine users. To explore this hypothesis we will 1) Identify among a cohort of HIV-1 positive, antiretroviral therapy naive individuals those cocaine-using and non-cocaine using individuals with virus carrying the MFNLP within the LTR. We will thereby have identified four groups for additional analyses: HIV-1 infected cocaine users with and without the MFNLP and non-cocaine users with and without the MFNLP. 2) Within the four groups quantify the expression levels within peripheral blood CD4 T lymphocytes and monocytes of c-fos and JunB, as representative immediate early gene components of AP-1. Similarly, using gel-shift assays or a new high throughput kit, we will quantify levels of AP-1 within those cell populations from the four groups. 3) Using 454 high throughput sequencing technology we will sequence the protease region to define within host genetic diversity and primary resistance mutations to PI. Using diversity, resistance mutations to PI and viral load as outcomes, we will examine using a multivariate analysis, the effect of cocaine use, immediate early gene expression levels, AP-1 quantities, and the presence of the MFNLP.